From "A Terrifying Round With A Menacing Metallic Clown," Velma goes cowering off with Scooby (she's got a clown phobia) to the pitching cages. As she's bracing for a pitch from Scooby, she gets a slice of pizza from the pitching machine Scooby is operating. She never realized cowering off could be so much fun.
Her turning down a Scooby Snack is also hilarious:
Velma: Nice try, Daphne; I may be scared, but I'm not desperate.
In "The Vampire Strikes Back", Shaggy and Scooby believe Fred has been turned into a bat by the vampire. They finally caught it until they found Fred. Realizing the bat is really a bat, Shaggy and Scooby ran away, with the bat flying after them, apparently taking a liking to them.